Field of the Invention
The present invention relates to a stent indwelling device.
Description of Related Art
In the related art, a tube stent placed in a lumen tissue such as a bile duct, a blood vessel, or the like, is known (for example, see Japanese Unexamined Utility Model Application, First Publication No. S63-20854). In addition, a procedure of releasing stenosis by inserting a tube stent or a metallic stent into a narrowed portion of the bile duct, and performing drainage of bile is known. When an indwelling period of the tube stent is lengthened, a lumen of the tube stent may close and prevent the drainage. As one cause of the lumen of the tube stent closing, an end surface of the tube stent comes in contact with a bile duct wall, and an opening of the tube stent may be closed by the bile duct wall. A phenomenon in which the opening of the tube stent is closed by the bile duct wall is likely to occur in a relatively hard tube stent.
A tube stent provided to reduce the probability that the opening of the tube stent is closed by the bile duct wall is known. The tube stent can be placed along a shape of the lumen tissue because a structure or a material is devised to provide flexibility. In Japanese Unexamined Patent Application, First Publication No. 2010-136895, a thin and soft tube provided to improve kink resistance and tensile strength is disclosed. The tube has a coil layer formed of an element wire constituted by a flat wire, and an outer layer having flexibility and arranged outside the coil layer. An outer surface of the coil layer and an inner surface of the outer layer are fixed to come in contact with each other in a slidable state. In addition, a stent indwelling device provided to place a flexible tube stent is known.